set 1 MCQ Questions & Answers Detailed Explanation

Question : 1

Photosynthesis occurs in

a) Only day

b) Day or night

c) Day and night

d) Night

Question : 2

Which one of the following gases is used by plants in photosynthesis?

a) Sulphur dioxide

b) Chlorine

c) Carbon dioxide

d) Ammonia

Question : 3

Which of the following types of light are strongly absorbed by plants?

a) Yellow and violet

b) Indigo and yellow

c) Blue and red

d) Violet and orange

Question : 4

Which one of the following does not increase the amount of carbon dioxide in carbon cycle on earth?

a) Volcanic action

b) Decay of organic matter

c) Photosynthesis

d) Respiration

Question : 5

When the bark of a tree is removed in a circular fashion all around near its base, it gradually dries up or dries because

a) Roots do not receive oxygen for respiration

b) Tree is infected by the soil microbes

c) Roots are starved of energy

d) Water from soil cannot rise to aerial parts

Question : 6

Which light is most effective in photosynthesis?

a) Violet

b) Green

c) Blue

d) Red